#!/usr/bin/env python3

# This script uses Pygments and Python3. You must have both installed
# for this to work.
#
# http://pygments.org/
# http://python.org/
#
# It may be used with the source-filter or repo.source-filter settings
# in cgitrc.
#
# The following environment variables can be used to retrieve the
# configuration of the repository for which this script is called:
# CGIT_REPO_URL        ( = repo.url       setting )
# CGIT_REPO_NAME       ( = repo.name      setting )
# CGIT_REPO_PATH       ( = repo.path      setting )
# CGIT_REPO_OWNER      ( = repo.owner     setting )
# CGIT_REPO_DEFBRANCH  ( = repo.defbranch setting )
# CGIT_REPO_SECTION    ( = section        setting )
# CGIT_REPO_CLONE_URL  ( = repo.clone-url setting )


import sys
import io
from pygments import highlight
from pygments.util import ClassNotFound
from pygments.lexers import TextLexer
from pygments.lexers import guess_lexer
from pygments.lexers import guess_lexer_for_filename
from pygments.formatters import HtmlFormatter


# Pygments' token classes, mapped onto the --syn-* custom properties that
# cgit.css defines. The fallbacks are the palette those properties default to,
# so that the output stays readable under a stylesheet without them.
SYNTAX_COLORS = (
	(('k', 'kc', 'kd', 'kn', 'kr'), '--syn-keyword', '#000',
		'font-weight: bold'),
	(('kp',), '--syn-keyword', '#000', None),
	(('kt',), '--syn-type', '#010181', None),
	(('nc', 'nf', 'nn', 'ne'), '--syn-keyword-alt', '#0057ae', None),
	(('s', 'sa', 'sb', 'sc', 'dl', 'sd', 's2', 'sh', 'sx', 'sr', 's1', 'ss'),
		'--syn-string', '#bf0303', None),
	(('se',), '--syn-escape', '#f0f', None),
	(('si',), '--syn-interpolation', '#0057ae', None),
	(('c', 'ch', 'cm', 'c1', 'cs'), '--syn-comment', '#838183',
		'font-style: italic'),
	(('cp', 'cpf'), '--syn-preproc', '#008200', None),
	(('m', 'mb', 'mf', 'mh', 'mi', 'mo', 'il'), '--syn-number', '#b07e00',
		None),
	(('o', 'ow', 'p'), '--syn-operator', '#000', None),
	(('err',), '--syn-error', '#bf0303', None),
	(('gd',), '--red', 'red', None),
	(('gi',), '--green', 'green', None),
	(('lineno', 'linenos'), '--syn-linenum', '#555', None),
)


def style_defs(prefix='.highlight'):
	rules = []
	for classes, prop, fallback, extra in SYNTAX_COLORS:
		selector = ', '.join('%s .%s' % (prefix, c) for c in classes)
		decls = 'color: var(%s, %s)' % (prop, fallback)
		if extra:
			decls += '; ' + extra
		rules.append('%s { %s }' % (selector, decls))
	rules.append('%s .hll { background-color: var(--syn-mark-bg, #ffb) }'
		% prefix)
	return '\n'.join(rules) + '\n'


sys.stdin = io.TextIOWrapper(sys.stdin.buffer, encoding='utf-8', errors='replace')
sys.stdout = io.TextIOWrapper(sys.stdout.buffer, encoding='utf-8', errors='replace')
data = sys.stdin.read()
filename = sys.argv[1]
formatter = HtmlFormatter(nobackground=True)

try:
	lexer = guess_lexer_for_filename(filename, data)
except ClassNotFound:
	# check if there is any shebang
	if data[0:2] == '#!':
		lexer = guess_lexer(data)
	else:
		lexer = TextLexer()
except TypeError:
	lexer = TextLexer()

# highlight! :-)
# printout the css definitions for pygments' token classes as well
sys.stdout.write('<style>')
sys.stdout.write(style_defs('.highlight'))
sys.stdout.write('</style>')
sys.stdout.write(highlight(data, lexer, formatter, outfile=None))